Machine Learning

Tuesday, October 14, 2014

The Future of Very Large-Scale Integration (Conti…) - Stretchable electronics

Mechanically
stretchable electronics are virtually non-existing today. In order to reach the
“summum” of comfort, for electronic textiles and biomedical applications, the
electronics should be flexible and stretchable to a certain extent, in order to
follow all movements and deformations of the body parts onto/into which they
are integrated. A stretchable electronic circuit is considered as a number of
rigid or flexible component islands which are connected by elastic
interconnections (Fig.1).
Stretchable interconnections are achieved by embedding meander shaped metal
wires in an elastic base material (Fig
2). Stretchabilities of 50% and more using our technologies have
been obtained and also the possibility to embed components has been
demonstrated (Fig 3).
For implants, the stretchable electronics have to be biocompatible. The metal
wires and electronic components must be shielded from the biological
environment of the body. The BioFlex
project focuses on this aspect. Certain applications for monitoring body
functions are under development.

The electronics are embedded in stretchable
materials. To create dedicated shapes of these stretchable materials, for each
electronic design dedicated moulds are created. Special attention goes out to
make the moulded stretchable material bubble free. In places where rigid
components are placed, the areas are deliberately made a lot thicker to make it
locally less stretchable. (Fig
4). When stretchable electronics have to
be worn the whole time, it is important to make them more or less breathable.
These electronics will be more comfortable to wear. We try to integrate
different kinds of synthetic materials, especially non-wovens, in our designs
in combination with our standard stretchable materials. As our technologies are
embedded in a layer of stretchable polymers, it is possible to make the
circuits watertight. (Fig 5, 6)
The idea rose to make the stretchable electronics washable. And so, the sweet-project was born. Washability is important
when we want to use our technologies in health care. The electronics have to be
sterilized or washed before they can be reused. Also for the textile industry,
it is very important to be able to wash the clothes with integrated electronics
easily.